Recently, there has been great interest in improving the image quality such as granularity and sharpness in a color photographic light-sensitive material, particularly a color photographic light-sensitive material for taking a picture.
Various methods to improve granularity of a silver halide color photographic material are known. For example, it is described in British Pat. No. 923,045 that sensitivity can be increased without lowering granularity by dividing an emulsion layer into a higher sensitive emulsion layer and a lower sensitive emulsion layer both of which emulsion layers have substantially the same color hue while reducing the maximum color density of the higher sensitive emulsion layer to a lower value. Also, the sensitivity can be increased without lowering granularity or the granularity can be improved without lowering sensitivity, according to German Pat. No. 1,958,709 disclosing a method wherein a coupler having a faster reactivity of coupling is used in the higher sensitivity emulsion layer of two emulsion layers having different sensitivity and being sensitive to the same color, and a coupler having a lower reactivity of coupling is used in the lower sensitivity emulsion layer of the two emulsion layers. Moreover, U.S. Pat. No. 3,843,369 discloses that granularity can be improved by providing a gelatin interlayer between a high sensitive emulsion layer and a low sensitive emulsion layer both of which high and low sensitive emulsion layers are sensitive to the same color, or by providing a medium sensitive silver halide emulsion layer having a low color density.
All these methods are an attempt to improve granularity at a practically important region of density by making the coupler used in a high sensitive emulsion react sufficiently to make a coarse granularity due to the high sensitive emulsion disappear, and the methods make the improvement possible.
However, because the requirement to improve the image quality is higher recently, these prior methods are insufficient in respect of the degree of improvement. Further, these methods have a fatal defect in that granularity in a shadow region or in the case of under exposure is remarkably coarse.
There are methods (described in U.S. Pat. No. 4,524,130) for preventing a color negative film from coarseness of granularity such as above, wherein the development activity is lowered by increasing the silver iodide content of a silver halide emulsion in a high sensitive emulsion layer and the granularity in a region of a low density can be improved by increasing the development inhibition by the presence of iodine (referring to T. H. James, The Theory of The Photographic Process, 4th Ed., page 418). But, in this case, the coupler added in the high sensitive emulsion layer does not react sufficiently and, thus, the coarse granularity in the high sensitive emulsion layer does not disappear, whereby there is a defect that coarse granularity in the high sensitive emulsion layer affects the regions of middle and high density. On the other hand, when, in order to improve granularity of the middle and high density regions, the development activity of the high sensitive emulsion layer is increased by lowering the silver iodide content thereof and granularity of the high sensitive emulsion sufficiently disappears, there is the defect that granularity in the region of low density becomes coarse.
A method of adding a so-called DIR compound in the high sensitive emulsion layer of a color negative film is also known which improves granularity in a region of low density affecting a high sensitive emulsion layer. But, as described in, for example, Japanese Patent Application (OPI) No. 97831/78 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application"), it is known that this method causes a lowering of the sensitivity and reactivity of a coupler in the high sensitive emulsion layer, to thereby inhibit disappearance of granularity and make granularity of regions of middle and high density coarse.
Accordingly, sufficiently good granularity cannot be obtained from regions of low density to regions of high density by prior methods. Further, improvement of granularity by using the coupler disclosed in British Pat. No. 2,083,640 or by increasing the amount of silver used results in deterioration in sharpness.